The OP can potentially lose a lot of weight by picking the right tire. At a claimed 840g weight, the Specialized Nimbus 26x1.5 would be a tire that I'd avoid. The Vittoria Randonneur Pro in 26x1.5 weighs 510g/tire. That's a difference of 660g for two tires, or 1.45lbs, which will be noticeable in my experience!